Apparatus for drafting textile fibers



May 7, 1968 A. L. MILLER ETAL APPARATUS FOR DRAFTING TEXTILE FIBERS Filed Jan. 6, 1966 6 Sheets-Sheet 1 FIGJ INVENTORS A.L. MILLER RS. BROWN C. L. SHEPARD ATTORNEY May 7, 1968 A. L. MILLER ETAL 3,381,343

APPARATUS FOR DRAFT ING TEXTILE FIBERS Filed Jan. 6, 1966 6 Sheets-Sheet 2 INVENTOIG A. L. MILLER R.S. BROWN C. L. SHEPARD ATTORNEY y 1968 A. MILLER ETAL 3,381,343

APPARATUS FOR DRAFTING TEXTILE FIBERS Filed Jan. 6, 1966 6 Slagets-Sheet 3 INVENTORS A L. MILLER R 3: BROWN C.L.SHEPARD BY 4 i a X ATTORNEY May 7, 1968 A. MILLER ETAL 3,381,343

APPARATUS FOR DRAFTING TEXTILE FIBERS Filed Jan. 6, 1966 m E WWW B S 1 & L ARQ ATTORNEY A. MILLER ETAL 3,381,343

APPARATUS FOR DRAFTING TEXTILE FIBERS May 7, 1968 s Sheec-Sheet 5 Filed Jan. 6. 1966 PIC-3.9

INVENTORS @WW I H Mmms 1 ARC B E El y 8 A. L. MILLER ETAL 3,381,343

APPARATUS FOR DRAFTING TEXTILE FIBERS Filed Jan. 6, 1966 6 Sheets-Sheet 6 INVENTORS AL. MILLER R. S. BROWN C. L. SHEPARD ATTORNEY United States Patent APPARATUS FOR DRAFTING TEXTILE FIBERS August L. Miller and Roger S. Brown, New Orleans, and

Charles L. Shepard, Chalmette, La., assignors to the United States of America as represented by the Secretary of Agriculture Filed Jan. 6, 1966, Ser. No. 519,168 5 Claims. (Cl. 19-258) ABSTRACT OF THE DISCLOSURE This invention relates to an apparatus for improving the easy separation and alignment of a lap or strand of disoriented and entangled fibers. The lap or strand is firmly held between a first pair of parallel rolls which introduce the disorientedfibers into the apparatus and a second pair of parallel doifing rolls whose surface speed is greater than the first pair. The tightly held strand is then subjected to a multitude of discrete, intermittent, attenuating stages of relatively short length by means of two sets of vertically disposed, oscillating parallel drafting plates which intermittently force the fibrous material into a zigzag path thereby opening and stretching out the tangled masses.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to an apparatus for drafting textile fibers. More specifically, it relates to an apparatus for drafting, or attenuating, textile fibers of any length into a strand or lap having a more orderly alignment. Still more specifically, it deals with an apparatus capable of producing a multitude of discrete, intermittent, attenuating stages of relatively short length and any desired width whereby dioriented and entangled textile fibers in the form of a strand, lap, batt, or loose fibers are opened and stretched out sufiiciently to permit easy separation and alignment in a subsequent process. Another object of our invention is to provide novel methods for attenuating strands of partially oriented fibers into strands having more orderly orientation and for teasing tangled masses apart in short increments to produce the desired attenuation. The fibers are not physically damaged by the process.

In conventional textile fiber drafting systems, the attenuation is obtained by means of two sets of rolls, or rolls and aprons in which the surface speed of the output rolls is greater than that of the input rollsQSufiicient pressure is applied between top and bottom. rolls to prevent the fiber from slipping. The distance between these adjacent pairs of rolls must be greater than the length of the longest fiber being processed in order not to break the fibers. In ordinary practice, the distance between rolls is usually one-sixteenth inch longer than the length determined by the classer.

For some fibers, especially the longer ones, pin drafters and gill boxes may also be used. In these dr-afters rows of pins penetrate the fiber in the drafting Zone and move with the fiber but at a faster or slower speed so that the fibers are pulled between the pins. This helps to align the fibers. In the pin dnafter and gill box, the only force attenuating the fibers is the pull due to the differences in speeds between the two pairs of rolls, the pins merely helping to align the fibers.

These prior art machines for drafting fibers serve a useful purpose in more fully aligning fibers prior to spin- 3,381,343 Patented May 7, 1968 ning. However, they have the serious disadvantage that they are unable to handle fibers that have not passed through the carding machine where the disoriented and entangled fibers are pulled apart at high speeds. This carding usually results in some physical damage to the fibers with its attendant disadvantages in subsequent process. Most important, these prior art drafting machines cannot be installed ahead of the card to aid and assist in the teasing apart of entangled masses of fibers prior to carding.

Accordingly, one object of the present invention is to provide an apparatus and method that gently teases apart laps or strands of disoriented and entangled textile fibers. The laps or strands are attenuated by the process. These laps or strands may be of any desired width.

Another object is to provide an apparatus that may be installed prior to, as .a part of, or subsequent to the carding machine. Still another object is to provide a method of introducing into the rapidly rotating surface of the card lickerin, laps of opened and stretched out fibers which permit easy separation during carding. Other objects will appear as the description of the invention proceeds.

In general, in accordance with the invention, the above objects are achieved by providing an apparatus and 'meth od capable of producing a multitude of discrete, intermittent, attenuating stages of relatively short length through which the fibrous textile material will progress in alternating zigzag and essentially straight paths, so that the elongation per cycle of the fibrous textile material is small, but the number of effective cycles is many. In eifect, the masses of disoriented, entangled, textile fibers are gradually teased apart in short increments (about 0.25 inch) to produce the desired attenuation.

In order that the invention may be fully understood, reference is made to the following detailed description and to the accompanying drawings in which:

FIGURE 1 is a schematic diagram showing the basic parts of the apparatus of the invention. Here the drafting plates are rectangular and in the disengaged (spaced) position.

FIGURE 2 is a schematic diagram showing the basic parts of the invention with the drafting plates in the engaged (juxtaposed) position. In this figure the bottom edges of the vertically disposed bottom drafting plates are supported by a movable supporting base mounted from a main frame.

FIGURE 3 is a schematic diagram showing one method of controlling the movement of the fibers through the apparatus of the invention. In this diagram the top grid and the bottom drafting plates are movable, while the bottom grid and top drafting plates are stationary.

FIGURE 4 is a schematic diagram showing the apparatus of FIGURE 3 in the engaged (juxtaposed) position.

FIGURE 5 is a schematic diagram showing the drafting plates in a triangular, or corrugated, cross-sectional form.

FIGURE 6 is a schematic diagram showing another method of controlling the movement of the fibers through the apparatus of the invention.

FIGURE 7 is a schematic diagram showing an application of our invention in which one set of plates oscillates for drafting and the other set vibrates for disentangling the fiber.

FIGURE 8 is a side view showing the preferred apparatus for drafting a lap of disoriented and entangled fibers.

FIGURE 9 shows one type of sawtooth onthe drafting plates.

FIGURE 10 is a schematic view showing the driving mechanisms for the apparatus of FIGURE 8.

FIGURE 11 is a schematic diagram showing a design of an apparatus as a two-stage unit.

As shown in FIGURE l.the apparatus comprises two sets of parallel drafting plates vertically disposed to each other and alternately (individually) spaced, between which the fibrous textile material moves. The top-drafting plates 3 and bottom drafting plates can be any number of drafting plates, depending upon the number of drafting stages (zones) desired for a particular process. Each space, between two drafting plates, constitutes a drafting zone. The plates 3 can be mounted as an integral part of top base support 4 which is rigidly supported by main frame 31, through a bracket (not shown), or the plates can be independently mounted. Bottom drafting plates 5 and bottom movable support base 6 also are supported by main frame 31, through guidepost 33. Both top and bottom plates can be movable to oscillate vertically, or either one can be movable and the other stationary. The fibrous material 9 can be delivered and removed from the mechanism by any conventional means and can travel continuously or intermittently. In FIGURE 1, the textile fiber is fed in by a pair of rolls 7a and 7b and removed by a pair of rolls 8a and 8b. The surface speed of rolls 8a: and 8b is always greater than rolls 7a and 7b by the additional length of fibrous material made available by the drafting. The draft is accomplished when the plates are engaged (juxtaposed) as shown in FIGURE 2, and the fibrous material is forced into a zigzag path, which is longer than the straight-travel path, shown in FIGURE 1. The amount of draft per cycle of the drafting plates depends on the spacing of the plates, the distance of engagement between plates, the number of plates, the rate of feed, and the initial tension or slack in the fibrous textile material. All of these items can be controlled and varied to produce drafts in a. range exceeding the upper and lower limits required in the field of textiles, e.g., drafts of 1 to 100 can be obtained.

It is a critical feature of the apparatus of our invention that the drafting plates are individually spaced apart with unimpaired lateral clearance in excess of a single-plate width so that the fibers are not physically damaged as the plates engage.

Drafting plates 3 and 5 can be made of any suitable material such as metal, plastic, etc., and fastened by any suitable means such as welding, clamping, screws, etc., to the support members 4 and 6 which, in turn, are fastened to or mounted from the main frame 31. The working edges 14 of plates 3 and 5 can be square, round or any shape, rough (rugose) or smooth, or covered with sawteeth, pins, or other points of sufficient length to get partial or full penetration of the fibrous material, and the working edges of the two sets of plates can be different from each other. The points can be in line with the plates or inclined in either direction. The dimension of plates 3 and 5 across the width of material being processed can be small enough to accommodate a single strand (about 0.5 inch) or large enough to draft a full size lap, or loose cotton batt, such as is normally fed to textile carding machines, i.e., about 40 inches.

Drafting by the preferred mechanisms of our invention is an intermittent process. Draft is inserted in the fibrous material when the plates are juxtaposed (engaged) as in FIGURE 2. This causes the textile fibers or fibrous material to form a zigzag path, and since the two ends of the strand or lap are held firmly by pairs of rolls 7a, 7b and 8a, 8b, the fibers slip, or are teased apart, thus increasing in length, and losing their entanglement. When the drafting plates are retracted (separated), as in FIGURE 1, the fibrous material 9 is free to move forward until such time as the plates engage again. Thus, there is a multitude of cycles in which the fibers first form a zigzag path and then an essentially straight path, which attenuates the strands, or teases apart the masses of entangled fibers. Thus, entering laps having a thickness of about one inch may be reduced to a thickness of about 0.06 inch when the draft is 16.

It is an advantage of the apparatus of our invention 4 that in order to more easily free the fibrous material from the drafting plates after each drafting cycle, and provide a more suitable surface on which the material can advance through the apparatus, a set of bars 10a can be inserted between drafting plates 3 and a second set of bars 10b between drafting plates 5 as shown in FIG- URE 3.

The top bars 10a are joined together at their ends by end-plate to form a top grid 21 which is supported by movable bottom base support 6 through brackets 63 and pins 62. These top bars 10a can oscillate between drafting plates 3 as shown in FIGURE 4. Bottom bars 10b are joined together by end plate 64 to form a grid 22, which is mounted on main frame 31 through bracket 61 and pins 65. Bars 10b are located between bottom drafting plates 5. Under the preferred operating conditions, bars 10b and drafting plates 3 are stationary. When cam shaft 32 revolves, it drives cam 29 which during one revolution raises and lowers (oscillates) bottom base support 6. As noted above, bottom drafting plates 5 and bars 10a are attached to support 6 and oscillate with it. Thus, each revolution of cam 29 produces one drafting cycle. The movements can be from the simple arrangement of one set of plates and one grid moving, to any combination of movements of the drafting plates and bars that will produce the desired relative motion.

When both sets of drafting plates 3 and 5 oscillate along with bars 10a and 10b, a second driving cam is required to drive top drafting plates 3 and bottom bars 10b. When this is done, the oscillating motion of the two sets of drafting plates is synchronized.

The bars 10a and 10b comprising grids 21 and 22 can be of any suitable flexible or rigid material such as sheets, solids bars, or slotted plates. Rigid preformed aluminum sheets for standard width machines (40 inches) is a good practice.

There are many variations of the drafting plates 3 and 5 which can be used. The plates may be rectangular in cross-section (FIGURE 1) or triangular (corrugated) as shown in FIGURE 5. The spacing can he varied from front to back, the amount of penetration (juxtaposition) between top and bottom plates can be varied by width of plates, or length of stroke. The configuration and angle of inclination of the plates also can be varied to produce different amounts, or rates of draft.

Another method of providing easy passage of the fibrous material through the apparatus of our invention is shown in FIGURE 6. The drafting plates 3 and 5 have stretched across their smooth working edges a sheet of rubber or other flexible material which has sufficient elasticity to stretch with the fibrous material 9 in FIG- URE 6 when the drafting plates are juxtaposed. This flexible material then recovers its straight line position when the plates retract (are spaced).

In addition to the normal oscillation of the plates required to draft the fiber, other movements of the plates can be of advantage in working the fibers apart. This is shown in FIGURE 7. The bottom drafting plates 5 are oscillated, as indicated by the dotted lines, by the cam 29, while the top drafting plates 3 are vibrated by electrical means 2. The frequency and amplitude of vibration of the top plates can range from very low into the ultrasonic range, and can be activated by electrical means, as shown, or mechanical or other means (not shown). The vibration can also be applied at the top, sides or ends of the plates and can be applied to one or both sets of plates, so that one or both sets of plates may oscillate and/ or vibrate.

A preferred mechanism for drafting a 40-inch fiber lap of entangled, disoriented fibers is shown in FIGURE 8. In this arrangement, the lap 9 is taken in by a pair of rolls, 7a and 7b, the top roll 7a being fluted and the bottom roll 7b having sawteeth pointing in the direction of the incoming fibers. These sawteeth prevent the lap from being pulled forward by the action of the drafting plates. The guide 36 keeps the lap against the roll 7b. The drafting of the lap takes place between the upper stationary drafting plates 3 and lower moving drafting plates 5, both of which have sawteeth on their working edges, see FIGURE 9. Top drafting plates :3 are secured to top base support 4 which is comprised of bars bolted together and mounted by a bracket 61 and supported by main frame 31. Bracket 61 also supports bottom grid bar's b which are stationary and held in position by pins 65. The bottom drafting plates 5 oscillate with sufficient stroke to juxtapose between the top plates 3 to such a distance as will give the desired draft, usually between 0.25 and 0.50 inch with most textile fibers. The oscillating motion is provided by cams 29, one at each side of the machine. The cams are mounted on a common shaft 32. The cams rotate in a bearing 46 to impart motion to the follower 47. This follower is held in position by guide pin 48 which is fixed in the follower and extends into a slot 49 in fixed bracket 61. The slot 49 may be straight or curved, vertical or at an angle, to provide various motions. The fol-lower has a circular motion at one end due to rotation of the cam, and a straight line motion at the other end as guided by the pin 48 in slot 49. The bottom drafting plates 5 are secured to bottom base support 6 which consists of four bars bolted together and are mounted at each end from the follower -47. A sideward rocking motion, in addition to the oscillating motion, is imparted to the drafting plates 5 by the action of the cam 29 and follower 47. The top grid bars t10a are also fastened to the follower 47 by screws 51, and oscillate with the bottom drafting plates. There are other mechanisms for providing the oscillating motion known to those skilled in the art. After the lap is drafted it passes through roll-s 8a and 8b which are fluted and slightly meshed to provide sufficient traction for pulling the drafted lap out and preventing it from being pulled back by the drafting action of the plates. The drafted lap is then delivered to the card feed roll or other mechanism that might be employed for further processing.

A typical method of imparting oscillating motion to the apparatus of FIGURE 8 is shown in FIGURE 10. The camshaft 32 is driven by belt :50 and pulleys 5'11 and 52 from the main cylinder shaft 53 of the carding machine. Cam '29 is secured to and rotates with shaft 32 to impart oscillating motion to follower 47 and drafting plates 5. Sprocket 54 also is secured to shaft 32 and is connected by chain 55 to sprocket 56 which, in turn, is secured to the shaft of bot-tom doffing roll 8b. The top and bottom dofling rolls 8:: and 8b mesh together to revolve as a unit, or may also be geared together. The input rolls 7a and 7b are also geared together (gears not shown), and are driven by the card feed roll drive shaft *57 through pinion 58 and gear 59. Variations in speed can be achieved by using different diameter pulleys, sprockets, and/or gears.

There are many variations and arrangements of the drafting apparatus that can be used for accomplishing satisfactory results. FIGURE 11 shows a schematic view of a drafting apparatus which is divided into two drafting sections with a pair of intermediate rolls a and 1512. These rolls 15a and 15b serve as dofling rolls for the first section and feed rolls for the second section. After passing through the drafting zones, the drafted lap is carried out by dofiing rolls 8a and 8b. Rolls 8a and 8b rotate faster than rolls 15a and 15b which, in turn, rotate faster than rolls '"7a and 7b. As the lap of entangled fibers is drafted, the lap becomes thinner and longer. The rotation of the rolls can be continuous, or intermittent. Intermittent rotation would normally be used for rolls 15a and 15b and 8a and 8b, said rolls rotating only when the drafting plates are separated. In the arrangement of FIGURE 11, the top drafting plates 3 and the lower grid 22 are stationary. The upper grid 21 is held in alignment by guides (not shown) and is free to move up or down. Said upper grid is supported by extension arms 28 from follower 47 so that as drafting plates 5 move up to mesh (engage) between top drafting plates 3, the grid 21 is raised to provide clearance. The up and down motion of the lower drafting plates 5 is provided by cam 29 rotating around .drive shaft 32 so that the follower 47 will move up and down with a wobble motion between guides 26. Guides 26 can be rollers, or sliding contacts. This wobble motion will cause the plates to engage in a nonparallel relation so that the front plates will penetrate before the back plates, and all plates will be at full penetration only momentarily before disengaging takes place from front to back. The drive shaft 32 extends across the width of the machine, and there is a cam 29 and follower 47 at each side of the drafting apparatus. The shaft 32 and rolls 7a and 7b, 8a and 8b, 15a and 15b, can be driven by belt, chain, gears, or other conventional means from another unit of the machine or independently from an electric motor. The wobble motion of the drafting plates 5 can be varied to produce different degrees of side motion by the location of the point on arm 28 which makes contact with guide 26. The closer the point of contact is to the upper edge of the plates, the smaller will be the side motion and angle of engagement. The guides can also use rolling instead of sliding contact.

The apparatus of this invention is capable of drafting a lap of disoriented and tangled fibers thereby reducing the weight per unit length of the lap without breaking its continuity. The apparatus is also capable of aligning the untangle-d fibers and orienting the tangles 0f fibers.

Although our invention has been discussed in relation to drafting laps of disoriented fibers, it works equally well for drafting fibrous strands produced by standard textile carding, drawing, and roving processes.

As a practical example of the method of attenuating fibers by the apparatus of this invention, a lap 9' of entangled, disoriented fibers is fed into rolls 7a and 7b at 0.060 inch per each drafting cycle. When the apparatus is adjusted to produce a draft (attenuation) of 16, pick off (dofiing) rolls 8a and 812 will Withdraw about one inch about one inch of lap in which the entering, disoriented, and entangled fibers have been opened and stretched out sufficiently to provide easy separation and alignment in a subsequent process. Here the draft (attenuation) is 16. Thus, an entering lap weighing about 16 oz./ yd. will be picked off at about 1 oz./ yd.

We claim:

ll. An apparatus for drafting textile fibers which comprises:

a) a plurality of bottom-edge-supported, uniform regularly shaped, essentially parallel, vertically disposedplates, individually spaced apart with unimpaired lateral clearance in excess of a simple-plate width defining, together with a supporting frame, a first set of drafting plates;

(b) plurality of top-edge-supported, uniform, regularly shaped, essentially parallel, vertically-disposed plates, individually spaced apart with unimpaired lateral clearance in excess of a single-plate width defining, together with a supporting frame, a second set of drafting plates, the edge of each plate distal the support edge provided with a fiber working edge, said second set of drafting plates positioned with the fiber working edges of the individual plates opposed to, and offset from, the corresponding Working edges of said first set of drafting plates;

(c) drive means adapted to impart oscillating motion relative the first and second set of drafting plates, the amplitude of said motion being sufiicient to move the opposed fiber working edges of said first and second sets of drafting plates from spaced to past juxtaposition, thereby forming a plurality of drafting zones;

(d) means for feeding the textile fibers to be attenuated into the drafting zones;

(e) means for disengaging the textile fibers from the working edges of the drafting plates when the plates are retracted, thereby permitting the fibers to move forward;

(f) pick-off means for removing the attenuated fibers from the drafting zones; and

'(g) separate drive means connected to the fiber feeding and the fiber pick-off means.

2. An apparatus as defined in claim 1 wherein the fiber feeding means consists of parallel rolls wherein the surface of one of the rolls is fluted and the surface of the other roll has sawteeth, said sawteeth pointing in the direction of the incoming fibers.

3. An apparatus as defined in claim ll wherein the pick off means consists of a pair of parallel rolls, said rolls being fluted and slightly meshed.

4. An apparatus for drafting and attenuating textile fibers which comprises:

(a) a plurality of bottomedge-supported, uniform,

regularly shaped, essentially parallel, vertically-disposed, smooth edged plates individually spaced apart with unimpaired lateral clearance in excess of a single-plate width defining, together with a supporting frame, a first set of drafting plates;

(b) a plurality of top-edge-supported, uniform, regularly shaped, essentially parallel, vertically-disposed, smooth edged plates individually spaced apart with unimpaired lateral clearance in excess of a singleplate width defining, together with a supporting frame, a second set of drafting plates, said second set of drafting plates positioned with the unsupported edges of the individual plates opposed to, and offset from the corresponding edges of said first set of drafting plates;

(c) drive means adapted to impart oscillating motion relative the first and second sets of drafting plates, the amplitude of such motion being sutficient to move the opposed faces of said first and second sets of drafting plates from spaced to past juxtaposition, thereby forming a plurality of drafting zones;

((1) means for feeding the textile fibers to be attenuated into the drafting zones;

(e) a separate elastic membrane enclosing each set of drafting plates for disengaging textile fibers from the drafting zones when the plates are retracted, thereby permitting the fibers to move forward;

(f) pick-off "means for removing the attenuated fibers from the drafting zones; and

(g) separate drive means connected to the fiber feeding and the fiber pick-off means.

5. An apparatus for drafting and attenuating textile fibers which comprises:

(a) a plurality of bottom-edge-supported, uniform, regularly shaped, essentially parallel, vertically-dis posed plates individually spaced apart with unimpaired lateral clearance in excess of a single-plate width defining, together with a movable supporting frame, a set of movable drafting plates;

(b) a plurality of top-edge-supported, uniform, regularly shaped, essentially parallel, vertically disposed plates individually spaced apart with unimpaired lateral clearance in excess of a single-plate width defining, together with a stationary supporting frame, a set of stationary drafting plates, the edge of each plate distal the supported edge provided with a fiber working edge, said set of stationary drafting plates being positioned with the fiber working edges of the individual plates opposed to, and offset from, the corresponding working edges of said set of movable drafting plates;

(c) a first set of bars, having flat surfaces, inserted between the stationary drafting plates, said bars being connected to each other to form a first grid, said first grid being secured to movable with the movable supporting frame;

(d) a second set of bars, having flat surfaces, inserted between the movable drafting plates, said bars being connected to each other to form a second grid, said second grid being secured to the stationary supporting frame, said sets of bars presenting essentially fiat surfaces to the textile fibers as said fibers move through the apparatus;

(e) drive means connected to the movable supporting frame and adapted to impart an oscillating motion to said movable supporting frame, to the movable drafting plates, and to said first grid, the amplitude of said motion being sufiicient to move the opposed fiber working edges of said sets of drafting plates from spaced to past juxtaposition, thereby forming a plurality of drafting zones;

(f) means for feeding the textile fibers to be attenuated into the drafting zones;

(g) pick-off means for removing the attenuated fibers from the drafting zones; and

(11) separate drive means connected to the fiber feeding and fiber pick-off means.

References Cited UNITED STATES PATENTS 456,155 7/1891 McGrath et al.

FOREIGN PATENTS 75,927 7/1894 Germany. 14,528 1892 Great Britain. 23,072 1912 Great Britain. 158,263 4/1922 Great Britain.

MERVIN STEIN, Primary Examiner.

DORSEY NEWTON, Examiner. 

